About max supply current in i.MX6Q.

[keitanagashima]

Dear All,

Refer to "Table 8. Maximum Supply Currents" in iMX6DQAEC(Rev.3).

Does MAX Current value include a AC components?

Or, is it MAX Current value with DC components?

Best Regards,

Keita

[igorpadykov]

Hi Keita

Table 8 gives DC currents values.

Best regards

igor

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[keitanagashima]

Hi Igor,

Thank you for your reply.

Do you have MAX Current values included AC components?

Keita

[igorpadykov]

Hi Keita

not, because AC currents depend on use case and calculated as describes

Table 8. Maximum Supply Currents footnote 5

General equation for estimated, maximum power consumption of an IO power supply:

Imax = N x C x V x (0.5 x F)

Where:

N—Number of IO pins supplied by the power line

C—Equivalent external capacitive load

V—IO voltage

(0.5 xF)—Data change rate. Up to 0.5 of the clock rate (F)

In this equation, Imax is in Amps, C in Farads, V in Volts, and F in Hertz.

Best regards

igor

[keitanagashima]

Hi Igor,

Hello.Thank you for your reply.

Please check my below comments again.

[Q1]

>not, because AC currents depend on use case and calculated as describes

>Table 8. Maximum Supply Currents footnote 5

I think that the equation is estimating for IO power supply.

How should I calculate AC current of VDD_ARM_IN and VDD_SOC_IN, etc?

[Q2]

Are all specification AC power associated "footnote 5"?

(I didn't understand the DC and AC parameters in Table 8. Maximum Supply Currents. Which parameter is AC spec? Which parameter is DC spec?)

[Q3]

Let me clarify my understanding.

My understanding is below.

- AC electric current : transiently-flowed current

- DC electric current : regularly-flowed current

If my understanding was wrong, please point out the DC MAX Current.

Best Regards,

Keita

[igorpadykov]

Hi Keita

1.>How should I calculate AC current of VDD_ARM_IN and VDD_SOC_IN, etc?

Processor does not use AC current, only DC.

Transients currents can not be calculated accurately.

2. Sorry, I didn't understand this question.

3. Only available data are given in "Table 8. Maximum Supply Currents" in iMX6DQAEC(Rev.3)

If You are speaking about transients currents, they can not be calculated accurately

and they should not be called as "AC" currents.

Best regards

igor

[keitanagashima]

Dear Igor,

Hello. Thank you for your quick reply.

> Processor does not use AC current, only DC.

OK. Thank you.

> 3. Only available data are given in "Table 8. Maximum Supply Currents" in iMX6DQAEC(Rev.3)

> If You are speaking about transients currents, they can not be calculated accurately

> and they should not be called as "AC" currents.

Is transients currents included in "Table 8. Maximum Supply Currents" ?

Best Regards,

Keita

[igorpadykov · Accepted solution]

Hi Keita

>Is transients currents included in "Table 8. Maximum Supply Currents" ?

Table 8 does not describe transients currents, that is very short in time.

All spikes/ripples are averaged and included in that figure.

Table specifies average current for normal conditions

(voltages comply with Table 6 Operating Ranges i.MX6Q Datasheet),

when allowed spikes/ripples do not exceed

5% Vp-p of supply voltage average value (Table 2-6 MX6QD

Hardware Development Guide)

Best regards

igor